Gauge for femoral trochanteric osteotomy



J. R. HERZ March 13, 1956 GAUGE FOR FEMORAL TROCHANTERIC OSTEOTOMY 5Sheets-Sheet 1 Filed Oct. 11, 1950 INVENTOR. dames Herz f r 1 .4 I I IATTNEK J. R. HERZ March 13, 1956 GAUGE FOR FEMORAL TROCHANTERICOSTEOTOMY 5 Sheets-Sheet 2 Filed Oct. 11, 1950 Q WQU mz we m Q HTTOR E).

J. R. HERZ March 13, 1956 GAUGE FOR FEMORAL TROCHANTERIC OSTEOTOMY FiledOct. 11, 1950 5 Sheets-Sheet 5 w mm"! March 13, 1956 J. R. HERZ2,737,724

GAUGE FOR FEMORAL TROCHANTERIC QSTEOTQMY Filed Oct. 11, 1950 5Sheets-Sheet 4 INVENTOR. dame: HQ/"Z 4770 NEK March 13, 1956 J. R. HERZ2,737,724

GAUGE FOR FEMORAL TROCHANTERIC OSTEOTQMY 7 Filed Oct. 11, 1950 sSheets-Sheet 5 w. am In I N V EN TOR.

2,731,724 GAUGE FGR- FEMORAL 'IIROCHANTERI'C OSTEOTOMY The presentinvention relates in general to bone and joint surgery; itdeals with thehip joint at the upper eX- tremity of the femur, or thigh bone; of thehuman skeleton, and refers specifically to femoral trochantericosteotomy.

By definition and association, osteotomy is an opera tion upon bonewhich involves cutting it, sometimes removing portions of it or addingportions to it, and moving the bone parts in space relative to oneanother. These parts must be allowed to knit in their new relationship,so it quite obviously is important in any osteotomy to provide somemeans for holding them fixedly in the desired position at least through;the post-operative healing period and perhaps permanently.

Osteotomy in the femoral trochanteric region is not new and, as a matterof fact, its theoretical soundness has been appreciated and itsimportance suspected for perhaps 100 years; however, the procedure hasseldom been used in practice because of the difficulty of immobilizingthe bone components satisfactorily in their desired position-adifiiculty which grows out of the irregular contour of the bone at theosteotomy site, and the literally infinite number of variations thatthere may be in the desired final disposition of the bone" components.The fixation devices heretofore available are poorly tolerated byelderly individuals: (in whom the majority of such operations would bedone) or are in'eflicient, inelastic in application, and unversatile.Internal splints, for example, are rigid in construction and applicableas a rule only to one type of operation. Conseqently, the majorproportion of the cases amenable to femoral trochanteric' osteotomy gobegging, and, where the procedure is employed, the bone componentsordinarily are fixed at best by inefiicient means such as wire screws,nails, etc.

It is an object of the present invention, broadly speaking, to remedythe foregoing situation. More particularly it is my aim to provide amethod and apparatus for effectingtthe internal fixation of bonecomponents in the case of a femoral trochanteric osteotomy, which methodand apparatus are characterized by such flexibility as to make themapplicable to all operations in this region, regardless of the bonecontour and regardless of the desired final disposition of the bonecomponents.

To this end it is an important object of the invention to provide amethod and apparatus for very rapidly and very accurately forming andfabricating an internal fixation device to conform to any bone contourand any disposition of bone components likely to be encountered in afemoral trochanteric osteotomy, whereby, in the course of the operation,the fixation device can be fashioned by or under the supervision of theoperating surgeon to fit the particular situation at hand, and appliedto the bone components at the osteotomy site to hold them securely inthe desired position.

A feature of the invention resides in the provision and use of a gaugeof novelconstruction for quickly and accurately. analyzing andregistering the relative position of the bone components after theoperating surgeon has nited States Patent *C) 2: made the desired cut orcuts in the femur, andhas relocated the components to achieve thedesired end.

Another feature lies in the provision of novel tools which are used inconjunction. with the aforementioned gaugeto rapidly shape a fixationdevice whichwill accurately conform to the contour and position of therelocated bone components and which may be secured thereto quickly andeasily;

According to my invention, I employ a: tw'oepart fixation device,namely, (1) a multi-flangenail adapted to be positioned axially of thefemoral neck, and (2') on in'ter trochanteric osteotomy plate or splint.extending from the end of the nail along the side of the femoral shaftand secured thereto; a further feature resides in an improved form ofconnection between thenail and the plate whereby the two are easilyconnected to onev another iii the correct relationship, and, whenconnected, are very securely locked against any change in theirrelationship so that they become in effect a single permanently rigidunit.

Other objects of the invention together with the features of noveltywhereby such objects are achieved will appear in the course of thefollowing description.

In the accompanying drawings which form a part of the specification andare to be read in conjunction therewith, and in which like referencenumerals are employed to indicate like parts in the various views:

Fig. l is an elevational view of the upper extremity of a femur showingits relation to thepelvic bone and illustrating a common type offracture amenable to trochariteric osteotomy.

Fig. 2 is a view similar to Fig; l, partiof the femur being broken awayto show in elevation the nail employed according to my invention.

Fig. 3 is a similar view illustrating typical cuts made by the operatingsurgeon in a femoral trocha'nteric osteotomy.

Figs. 4 and 5 are views showing by way of example two basic alternativemanners in which the bone components can be relocated after the cutsillustrated Fig. 3 have been made, the choice between the two iying withthe operating surgeon and being determined by the. condition of thepatient, what the surgeon desires to achieve, and various factors; Fig.4 represents an angulational' ste'otd my, while Fig. 5 represents anangulational transpositiona1 osteotomy. In each case aninter-'trochanteric osteoto my plate formed according" to the inventionto fit the particular case is femoral shaft.

Fig. 6 is a view corresponding to Fig; 4' but showing in the place ofthe inter-trochanteric osteotomy plate, one form of gauge according tothe invention, arranged in position to register the relationship of therelocated bo'ne components preparatory to fashioning the plate to fitthem; parts of the femur and nail are broken away for purposes ofillustration and the gauge is sh'ow'rrpartly in section and partly inelevation.

Figs. 7 and 8 are plan andside' elevati'onal views'respec tively of theinter-trochanteric osteotomy plate Before bending thereof, the shapeafter bending'for' use in the" osteotomy of Fig. 4 being indicated bythe dotted lines in Fig. 8.-

Fig. 9 is a plan view of the apparatus employedto' bend theinter-trochanteric osteotomy plate for the Fig. 4' osteotomy,illustrating the mode of use ofth'e tool's.

Fig. 10 is a cross sectional view taken along the line" 10-10 of Fig. 9in the direction of the arrows.

Fig. 11 is a cross sectional view taken along" the line 11-11 of Fig. 9in the direction of the arrows.

Fig. 12 is an exploded perspective view of the gauge shown-in Fig. 6., v

Fig. 13 is a view corresponding to Fig. 5 but showing shown secured tothe nail and thein place of the inter-trochanteric osteotomy plateanother form of gauge I employ to register the relationship of therelocated bone components preparatory to fashioning the plate to fitthem, the gauge being shown partly in section and partly in sideelevation.

Figs. 14 and 15 are plan and side elevational views respectively of theinter-trochanteric osteotomy plate before bending thereof, the shape ofthe plate after bending for use in the Fig. 5 osteotomy being indicatedby dotted lines in Fig. 15.

Fig. 16 is a plan view of apparatus employed to bend theinter-trochanteric osteotomy plate for the Fig. 5 osteotomy,illustrating the mode of use of the tools.

Fig. 17 is a fragmentary perspective view of one of the tools shown inFig. 16.

Fig. 18 is an exploded perspective view of the gauge shown in Fig. 13.

Fig. 19 is a perspective view of a modified form of gauge which may beused to register the position and relationship of the relocated bonecomponents in an angulational osteotomy, a transpositional osteotomy, oran angulational-transpositional osteotomy.

Fig. 20 is an edge elevational view of the combination gauge shown inFig. 19.

Figs. 21 and 22 are views illustrating the manner in which mycombination gauge is used, Fig. 21 showing its use in an angulationalosteotomy, and Fig. 22 showing its use in anangulational-transpositional osteotomy.

Fig. 23 is an enlarged cross sectional view taken along the line 2323 ofFig. 4, in the direction of the arrows.

Fig. 24 illustrates an inter-trochanteric fracture of the femur, thebone components having been immobilized following an angulationalosteotomy which involved removal of a bone Wedge below the lessertrochanter to promote healing of the fracture.

Fig. 25 illustrates coxavera of the hip characterized by loss of thenormal angle of the femoral head relative to the shaft, as may resultfrom various causes.

Fig. 26 illustrates the correction of the Fig. 25 coxavera by anangulational osteotomy.

Fig. 27 illustrates coxavera accompanied by non-union or delayed unionof a fracture in the femoral neck region, as may result from a number ofcauses.

Fig. 28 illustrates the correction of the condition show in Fig. 27 byan angulational-transpositional osteotomy, the removal of the bone wedgeserving to restore the femoral head to substantially its normal angularrelationship to the shaft, and the medial transposition of the shaftserving to promote healing of the fracture and increase the stability ofthe hip joint.

Fig. 29 illustrates an arthritic hip joint characterized by loss ofjoint cartilage and fixed deformity of the femur relative to the pelvis.

Fig. 30 illustrates treatment of the condition shown in Fig. 29 byarthrodesis, or closure of the joint by a transfixation nail, and anangulational osteotomy (which may or may not be accompanied byshortening of the shaft) to correct the weight bearing alignment of thebone components.

Referring more particularly to Fig. 1, it will be helpful to outlinebriefly at the outset the principal physiologicoanatomical andgravitational factors that must be borne in mind in connection with afemoral trochanteric osteotomy. This figure illustrates the hip joint ofthe human skeleton, which comprises a pelvic bone 30 having a socket oracetabulum 31 that receives the ball-shaped head 32 of the femur, thecapsular ligament that encloses their cartilaginous surfaces having beenomitted for simplicity and clarity; proceeding from the head 32, theremaining portions of the femur shown are the neck 33, the greatertrochanter 34, the lesser trochanter 35 and the femoral shaft 36 which,it will be understood, extends downwardly to the knee.

The hip joint is one of the units in the motor skeletal system which iscapable of stability and a considerable degree of motion-a localmanifestation of which is the phenomenon of movement of the individualor parts of him through space. In that phase of the normal gait when onefoot is on the ground and the other is clear of the ground, the weighttransmitted as a gravitational force to the bodysupporting femur isrepresented by the arrow A. This force is met in the transverseneck-trochanteric region of the femur by an equal and opposite force Bprojected up the shaft 36 from the foot resting on the ground. Becausethe hip joint is spaced some 10 centimeters from the midline of thebody, where body weight is centered, the effect of leverage makes theseforces comparatively great; if body weight is kg. for example, theeffective thrust at A is a moment of 700 kg. cm.

Referring still to the weight-bearing side, the ball-shaped head of thefemur is fixed and cannot move to any great extent due to its continuitywith the ground. The pelvis cannot slip from the ball because thecontour of the socket or acetabulum and ligaments form a stable carrieragainst such movement. Since the body weight is medial to the head ofthe femur, the socket therefore tends to rotate or revolve downwardlyabout the head of an arc, and the crest of the iliurn on theweight-bearing side will rotate toward the spinal column. The individualwould fall at this moment were it not for the spinal column shiftingover the head of the femur to keep the center of gravity in line withthe lower extremity. The righting reflexes are responsible for theselatter movements which happen in the absence of a system of muscularchecks to prevent the arc of the pelvis. One might then divide thegravitational force into two parts, one tending to thrust down on thehead and neck of the femur with its counterpart from the shaft meetingit at the greater trochanter-neck region. The second part is aco-existing rotating, revolving, arcing force tending to swing thepelvis and acetabular socket downwardly about the head of the femur. Thelatter is opposed by still a third force C exerted principally by thegluteal muscles 37 which, by reason of their origin on the crest of theilium (not shown) and insertion into the greater trochanter 34, resistrotation of the pelvis and keep the same level. The contralateralerector spinae, quadratus lumborum and the tensor fascia femoris on thesame side as the gluteus medius and minimus assist the latter, but inthe main the gluteal muscles are the principal resistors of the greatgravitational force.

The neck-trochanteric region is the crossroad where this triumvirate offorces meets, and because of its offset crane-like structuralrelationship with the shaft 36, this region is the most vulnerable,being the first to bend, dislocate or break. Since all of the forcesboth gravitational (weight-bearing) and anatomical (muscular) areoperating in an integrated mechanism, it may be said that normal contourof the bone reflects the proper relationship in the distribution ofthese forces. Loss of continuity, shape and position, or loss of normalcontour, reflects abnormalities of bone structure, abnormally greatstress, or loss of soft tissue elements of the joint with consequentdisruption of normal joint function instability, loss of motion andpain.

Where there has been an abnormal change in contour of the upper femur,indicating a malfunctioning joint, such for example as after certaintypes of fracture, this may sometimes be remedied simply by immobilizingthe bone components in the correct normal anatomical position. For thisthere are many devices rigid in design and purpose. Assuming, forinstance, that there is a fracture 3'5 relatively transverse to the axisof the neck 33, it is a common practice to drive axially into the neck,as shown in Fig. 2, a three flange nail 46 (commonly known in theprofession as the Smith-Petersen nail) to immobilize the fumural headrelative to the trochanteric portion of theh femur. This may be all thatis necessary, but often such is not the case. This is partly due to thefact that the nail extending through the neck quite obviously reducesthe effective cross-sectional area of the neck so far 1 femur makes theas circulation of bloodtothe femoral headrisconcerned, andby thusimpairing circulation retards the unionoflthe bone components at thefracture zone. Added to this is the fact that the relationship of forcesA, B and=C to the transverse fracture 38 is such as to produce a strongtendency towards shear along the line .ofthe fracture, these forcesbeing capable of exaggerating greatly slight defects tending to disruptthe stability of the bone components meeting at the fracture line.

For these and other reasons it often is necessary or very desirable torechannel the forces A, .B and-C in relation to the fracture in such away as to utilize them to advantage in promoting rather than impairing.the union of the bone components at the fracture. This,-as Well as thecorrection or other deformities as will .be explained subsequently, isthe function of osteotomy.

In any osteotomy five spacialchanges in the bone components arepossible, namely, angulation, transposition, rotation, shorteningandlengthening. Inthe trochanteric neck region of the hip weareprimarily concerned with the first twoangulation and transposition, andtheir combination, angulation-transposition. The next two-rotation andshortening-are incidental or coexisting move ments most often associatedwith angulationand transposition, and rarely used for their effectalone. The:last, lengthing-is a movement unassociated with the presentproblem so finds no place here. 7 Referring to Fig. 3, angulationalosteotomy inthe trochanteric neck region of the hip involves cuttingfrom the femur a wedge 41, ordinarily by making cuts 42 and 43betweenthe lesser and greater trochanter, removing the wedge as indicatedbydotted lines, and tiltingthe headneck-greater-trochanter section tobring the cut surfaces 42 and 43 together as shown in Fig. 4. In apurely transpositional osteotomy (not illustrated) there would be no cut43, but only a cut 42, the upper end of the shaft 36 being advancedlaterally in a medial direction to lie under the fracture 38. Fig.illustrates a combination angulation-transposition osteotomy; here inaddition to removing the wedge 41 (Fig. 3) and tilting the'head-neck-greatertrochanteric section (Fig. 4) the upper extremity ofthe shaft has been transposed to the left so that it'lies under thefracture.

Referring to Figs. 4 and 5, it will be seen that the angulational shiftof the head-'neck-..trochanteric section of the fracture site morehorizontal relative to the shaft 36, thereby decreasing the effect ofshear along the fracture and enhancing the e'lfect'of compressionbetween the fragments on either side of the fracture site; in otherwords, forces A andB have been rechanneled to favor healing instead ofdisrupting the fracture. Where the femoral shaft is moved under theiheadand neck, as in the caseof a purely transp'ositiona'l osteotomy, or'in acombination transpositional-angulational osteotomy (Fig. 5) theweighhbearing stresses bypass the femoral neck, and to a large degreethe fracture, so that it is only the static muscle pull on the greatertrochanter (force 'F) which has any substantial disruptive effect uponthe fracture. Transposition also amounts in effect to a'bone graftbetween the upper extremity of the femoral shaft and the femoral headand neck which tends to augment the precarious blood supply in the headandneck, enhancing v-acularity and healing of the bone.

Once the operation has been completed (i. e., when'the necessary cutshave been made and the bone components relocated) it is necessary thatthey "be fixed or immobilized for a period sufiiciently long forthemtoheal. Otherwise, the normal anatomical forceC, even in theabsence ofweight bearing, due to static muscle pull will disrupt the bonecomponents. Disruption can occur in a plaster cast, the most common typeof external immobilization used in these cases. A salient feature of thepresent invention resides in the provision of an inter-trochantericosteotomy plate or external splint (identified by the numeral 44 in Fig.4 and by "the numeral 45 in Fig. 5) bridging the osteotomy site with oneend secured to the nail-40 and the other end secured by screws 46 to-thefemoral shaft.

The difference in the shape of plates '44 and 45, as shown in Figs. 4and 5, illustrates the'variation that may exist even in the same femurwith the same cuts, depending upon whether there is angulation only or acombination of angulation and transposition. In actual practice theposition of the cuts may also depart widely from the positions shown, inaccordance with what the surgeon wishes to do and what he finds in thecourse of the operation he is capable of doing. Taking these factors,plus the .inevitable variation in shape and contour between one femurand another, it can well beappreciated that the requirements as to theshape of the inter-trochanteric.splint rarely are alike in any twocases. Therefore an importantlphase of my invention resides .in beingable to form an intertrochanteric osteotomyplate orsplint very rapidlyin'the course of any operation to fit thersituation in hand. The means Ihave provided for doing this .now will be explained.

In the case of an angulational osteotomy, I first employ a gauge asshown in Figs. 6 and 12 to analyze and accurately register the positionof the bone components after they have been relocated as desired by theoperating surgeon. This gauge comprises a block 50 split longitudinallyto form a slot 51 extending inwardly from one end of the block to apoint .near'the opposite end. Between the legs thus formed is a thinfiatblade or arm 52 apertured at one end to receive a pivot screw 53extending through a hole 54 .in one leg of the block into an internallythreaded corresponding hole in the oppositel'eg. The head of the screwis knurled to facilitate turning same; when tightened it causes the legsof the block to securely clamp the arm 52 and thus prevent'movement ofthe latter, but when loosened the blade can swing freely on the screw.

In the slot 51 is threaded-shank 55a of an elongated pin 55 having anenlarged integral collar 55b intermediate the two sections of the pin.This collar is disposed in a shallow recess 56 in one face .of the blockand forms a shoulder abutting the bottom of the recess. The shank ofthepin is threaded but is flattened on two opposite sides as best seenin Fig. 12 so that the shank will slide longitudinally of slot 51 butcannot turn therein about its own axis. A knurled thumb-nut 57 isscrewed onto the end of the threaded shank 55a which projects out ofslotSl. When the nut is loosened the ,pin can'be shiftedlongitudinally'of the slot as suggested above, but when it is tightenedit clamps the pin securely to the block.

Referring to Fig. 6 the nail 4t} which I employ is cannulated to receivepin 55, the outermost end of its bore also being specially threaded tofacilitate subsequent attachment of the inter-trochanteric osteotomyplate thereto, as will be explained more fully hereinafter. in using mygauge, nut 57 and screw 53 first are loosened; pin 5d then is insertedinto the bore of nail 40 and, with the face of block 50 pressed firmlyagainst the end of the nail, the block is shifted longitudinally untilblade 52 will lie flat against the femoral shaft 36 as ".ShOWlJ. Withthe parts thus positioned, nut 57 and screw 53 are tightened, afterwhich pin 55 is withdrawn from thenail.

It-should be noted that the gauge .now offers a fixed and properlyintegrated registration of the two variables which will control thefashioning of the interatrochanteric osteotomy plate 44 (Fig. 4)na1nely,.the size of the angle x that exists between the side of the femoralshaft 36 and the .plane of the exposed end of nail 4i) and, second, thedistance y, this being the-distance from the axis of the nail 44B tothepoint at which'the bend in-the plate mustoccur.

In forming my inter-trochanteric osteotomy plate, I use the toolsillustrated :inEigs. :9, l0 and 11. These cornprise a pair .of elongatedbars wand 61 of rectangular 'crosssection, each bar being .groovedlongitudinally to 7 provide a narrow but rather deep slot 62 extendinginwardly from one end of the bar; the latter end has a pair of opposed,tapered or bevelled surfaces 63 disposed at an angle of to the axis ofthe bar, forming what will be referred to hereinafter as the nose of thebar.

Bar has secured thereto on one side of the slot 62 a plate 65 bearing aprotractor scale 66. At the center of this scale is a pivot pin 67carrying an arm 68 which may be clamped against movement by tightening aknurled nut 69 screw threadedly received on the pivot pin, or allowed toturn about the pin by loosening said nut. The arm has a sight aperture70 over the protractor scale, this having in one edge an index lined 71adapted to register with the markings on the scale; on the other side ofthe pivot the arm is formed with an L-shaped leg having a second indexline 72 adapted to function similarly.

For all femoral trochanteric osteotomies, regardless of the finaldisposition of the bone components, I fashion my inter-trochantericosteotomy plate utilizing a standard, preformed flat plate which isshaped, drilled and counterbored as shown by solid lines in Figs. 7 and8. The manner in which this is bent in the case of an angulationalosteotomy now will be described, it being assumed for purposes ofexplanation that the bone components have been relocated as shown inFig. 6 following removal of a bone wedge, and that the gauge also shownin that figure has been set as described hereinbefore to measure theangle x and the distance y.

First, it is necessary to locate the point at which the fiat osteotomyplate must be bent, and I prefer to lightly scribe a pair of parallellines 74 across the plate, marking the region between which the bendmust occur. The location of these lines is determined by measuring thedistance y on the gauge (by calipers or in any other suitable fashion)and then measuring off a like distance longitudinally of the plate fromthe center of hole 75 to fix the position of lines 74; with very littleexperience the operating surgeon can make appropriate allowance for theradius of the bend and the thickness of the plate in locating lines 74based upon the measured distance.

Next, the angle x on the gauge is measured (for instance by aprotractor) and arm 68 is set at a similar angle with the aid of theprotractor scale 66 and index line 71. The flat plate 44 now is insertedin slots 62 or bar 60 and 61 with the nose ends of the respective barslying on either side of lines 74; and bar 61 is swung up to a positionparalleling arm 69 (see Fig. 9), bending plate 44 at the proper placeand at the proper angle to fit the osteotomy at hand. When the plate nowis positioned as shown in Fig 4, it is only necessary for the surgeon tosecure it to the femoral shaft by screws 46 extending through thepreformed holes 76 (see Fig. 7) and anchor it to the cannulatedtransfixation nail 40 which already is in place extending axiallythrough the femoral neck.

It will be convenient at this point to refer to Fig. 23 which shows theform of connection I prefer to employ between the transfixation nail 40and the inter-trochanteric osteotomy plate 44. It will be noted that theend of the nail is internally threaded at 77 to receive a hollow screw78 extending through hole 75 in the plate; and it is further threaded at79 to receive a lock screw 80 extending through the bore of screw 78.Screw 78, which is tightened down first, may have a right-hand thread,while screw 84 has a left-hand thread (or vice versa) so that when thetwo are in place it is virtually impossible for screw 78 to work loose.

The head of screw 78 is countersunk, being tapered to fit thecounterbored face 82 of plate 44. The outermost extremity of nail 40 issimilarly tapered to seat in a counterbore 83 in the opposite face ofthe plate. Preferably the confronting or seating faces of the nail andcounterbore 83 are roughened or provided with radial serrations topositively prevent rotation of the nail about its axis when the twomembers are drawn tightly together,

so it will be seen that my arrangement forms an exceedingly strong andsecure connection between the two members, which in effect integratesthem as one permanently rigid unit.

Referring then to Fig. 4, it can be appreciated that the bone componentsare firmly braced and anchored by my arrangement so that they willremain fixed through the post-operative healing period. Moreover,because the inter-trochanteric osteotomy plate has been accuratelyfashioned to fit the particular situation at hand it is easily toleratedby the patient and the relationship in which the bone components aremaintained is the best suited to promote healing.

Let it now be supposed that the osteotomy involves, instead ofangulation of the bone components (or in addition thereto) transpositionof the upper end of the femoral shaft along the femoral neck in a medialdirection. In such a case I may use a gauge of the kind shown in Figs.13 and 18. Referring to the latter figure, the gauge comprises a block85 having near one end thereof a pin 86 projecting from one longitudinalface of the block at right angles thereto, the pin being secured to theblock by a set screw 87. A slot 88 extends inwardly from the oppositeend of the block forming opposed legs 89. Between these legs is a thin,flat blade 90 having a right angle projection 90 at the end thereof; athumb screw 91 passing through an aperture 92 in one of said legs into atapped hole in the opposite leg makes it possible to draw the legstogether in order to clamp the blade, which, it will be understood, isfreely slidable in slot 83 when the screw is loosened.

The manner in which this gauge is used will be evident from Fig. 13.With screw 91 loosened, pin 86 simply is inserted into the bore of thecannulated nail 40 and block 85 is pressed firmly against the exposedend of the nail. Blade 90 next is moved in the slot so that its edgeabuts again the corner 93 of the upper bone segment while the portion9!) lies against the distal side of the femoral shaft as shown; thenscrew 91 is tightened to preserve the position of the blade relative tothe block and the gauge is withdrawn.

Referring to Figs. 14 and 15, I now scribe two pairs of lines 94 and 95on the preformed, flat osteotomy plate 45 to be used, in order to markthe two places at which the plate must be bent. The position of lines 94is determined from the gauge by measuring the distance x (i. e., thedistance from the center of pin 86 to the corner 96 formed by the block85 and blade 90see Fig. 13) while the position of lines 95 is determinedfrom the gauge by measuring the distance y (i. e., the distance fromcorner 96 to the end of blade 90).

Using the tools illustrated in Figs. 9, 10 and 11, in the mannerpreviously described, plate 45 next is bent in the region between lines94; in doing this, arm 68 of the bar 60 is set to conform with the anglez measured from the gauge, so, as shown in Fig. 15, the initial bend inplate 45 will cant the tip of the plate at the angle z relative to themain body of the plate.

It now is necessary to form a 90 bend in plate 45 between lines 95, andfor this purpose I use, in conjunction with bar 60 or bar 61, anotherbar-like tool 97 shaped as shown in Figs. 16 and 17. This has a nose 98at 45 to the longitudinal axis of the bar, and at the junction of thenose and one side of the bar, a narrow slot 99 extends transverselyinward to an open pocket 161). It will be noted that the forward wall ofthe slot is coplanar with the forward wall of the pocket and in factforms an extension thereof, the tip of the bar being shaped as a righttriangular prism. The canted end of plate 45 is placed in pocket 100with the straight portion of the plate projecting through slot 99 andextending laterally from the bar; the projecting portion is inserted inslot 62 of bar 60 or bar 61, whichever may be more convenient. With thenose of the latter bar and the confronting longitudinal face of bar 97positioned on either side of the lines 95 and 9 closely adjacentthereto, bar 97 is swung through 90 or until its nose 98 parallels thenose surface 63 of bar 60 (or 61) as shown in Fig. 16, which forms a 90bend in plate 45 at the proper location.

With the plate thus bent at the two places determined by the distances,x' and y, it will accurately fit the relocated bone components as shownin Fig. 5. When it is connected to the transfixation nail 40 by the lockscrew arrangement discussed in connection with Fig. 23, and is securedto the distal side of the femoral shaft by screws 46, it formsa-fixation unit which anchors and supports the bone components rigidlyin the position selected by the surgeon.

Although Figs. and 13 illustrate an osteotomy involving both angulationand transposition, it will beunderstood that the same gauge-would beemployed in a purely transpositional osteotomy (i. e., one not involvingre moval of a bone wedge) and also that the same basic method would befollowed in bending the inter-trochanteric osteotomy plate, but thefinal shape of the plate naturally would be different due to thedifferences that would exist in the measured distances x and y and inthe angle 2'.

Figs. 19 to 22 illustrate a modified form of gauge which is suitable forregistering the necessary angles and distances involved in any femoraltrochanteric osteotomy whether the osteotomy involves angulation alone,transposition alone, a combination of angulation and. transposition, orany of the foregoing in combination. with shortening and/or rotation.This gauge comprises a block 102 having a slot .103 extending inwardlyfrom one end and a pair of slots 104 extending inwardly from theopposite end, the latter lying on either side of the first-mentionedslot. In the slot 103 at one end of the block is a thin blade 105apertured to receive a pivot screw 106 extending transversely of theblock; this screw preferably is tightened down sufiiciently to cause.the legs 102' to exert some frictional force on the sides of the bladewithout tightly binding it, the blade: therefore being manually movableby light finger pressure but being adapted to remain in any position towhich it is thus moved.

At the opposite end of the block is a channel member or finger 108.U-shaped in transverse cross section, this has at one end a pair ofintegral, laterally spaced parallel legs I09 disposed at right angles tothe longitudinal axis of the finger. The latter legs are disposed inslots 104' and each has an elongated aperture 110 through which theshank of a thumb screw 111 extends. When the screw is loosened it willbe seen that legs 109 can slide freely in slots 104 and turn about thescrew, but when it is tightened they are clamped against suchmovement.

A pin 112' which is substantially identical to pin 55 (Fig. 12) has itsflattened shank extending through slot 103'; the threaded end of thisshank projects beyond block 102 and is screwed into tapped hole in theend of handle 113. Thus when the handle is tightened, pin 112' isclamped" securely to block 102 and cannot move, but when it is loosened,the pin may be shifted longitudinally of the slot. H

The manner in whichthis gauge is used in the case of an angulationalosteotomy is illustrated in Fig. 21'. With handle 11'3 loosenedslightly, pin 112' is inserted in the bore of the cannulated nail 40;blade 105 is positioned toward the femoral shaft and block 102 isadjusted in an endwise direction until it and the blade 105 occupy thepositions shown. Then handle 113 is tightened and used to Withdraw thegauge which, it will be seen, now registers the distance x and the angley so that on the basis of these measurements the surgeon can bend thefiat osteotomy plate to fit the relocated bone components as describedhereinbefore.

In: the case of a transpositional osteotomy or anangulational-transp-ositional osteotomy, the gauge is used as shown inFig. 22. Here again finger 112 is inserted in 10 the cannulated nailwith handle 113 slightly loosened. Screw 111, alsois loosened and: thegau-geparts arexadjusted to the position shown, wherein finger 108 liesalong the distal side of the femoral. shaft, legs 109 abut the corner of.the upper bone segment and block 102 is tight againsttheendof the nail40. Then screw 111 and'handle 113 are tightened and the latter is usedto remove the gauge with the parts thus set in proper position. Inbending the inter-trochanteric osteotomy plate, the surgeon usesmeasurements of the distances x and y and the angle vz as previouslydescribed.

From the discussion and explanation which has been givenabove, it shouldbe clear to those versed in the art how my invention .is adapted,with-out any fundamental departure from the principles disclosed, tomeet the many varying situations that may be encountered in practice. Afew representative conditions that have been treated according to theinvention are illustrated in Figs. 24 to 30.

Fig. 24 shows an inter-trochanteric fracture which has been immobilizedby the transfixation nail 40. To reduce the tendency toward shear alongthe fracture line, and to-utilize the gravitational and anatomicalforces to promote healing, an angulational osteotomy has been performed;that is to say, a bone Wedge 121 has been. removed to increase the pitchangle of the femoral headneck regi-onand make the fracture more nearlyhorizontal. It will be understood that in this case, as in the othersdiscussed, the angul'ational osteotomy may be accompanied by shorteningor rotation if such is desirable or necessary; if shortening isinvolved, the removed bone wedge might, for example, take the shape121'.

Fig. 25 illustrates coxavera or loss of the normal angle of thecrane-like upper portion of the femur, which results in a droopingfemoral head. Such an abnormal condition (which may have various causes)is corrected by removing a wedge 122 and, by means of my invention,

relocating the, bone components as shown in Fig. 26, so

that approximately the normal angle of the head is restored.

Fig. 27 shows coxavera. accompanied by non-union or delayedv union of anold fracture 123 in the femoral-neck region. As. aremedial measure, anangulational-transpositional. osteotomy is performed as shown in Fig.28, the transfixation nail 40 being driven through the femoral neckacross the fracture zone and a bone wedge 124 being removed to restorethe head to approximately its normal angle; the medial transposition ofthe femoral shaft helps.

to stabilize the joint and promotes healing by augmenting the bloodsupply and, in effect, forming a bone graft bridging the fracture.

Fig. 29 illustrates an arthtritic hip joint which may be treated byarthrodesis as shown in Fig. 30. As indicated, the femoral head isrigidly fixed in the acetabular socket by driving a transfixat-ion nail40 axially through the femoral neck and into the pelvic bone. To correctthe fixed deformity of the femur relative to the pelvis and improveweight bea-ring alignment, an angulational osteotomy is performed, thatisto say, wedge 125 is removed and the bone component's relocated asshown in Fig. 30.

In each of the foregoing operations, my flat, intertrochantericosteotomy plate is bent to fit the particular need, using the gauges andbending tools described hereinbefore. The flexibility of my apparatusmakes it possible in any such.- operation to fashion the requisite platerapidly and accurately in the course of the operation, and insuresproper immobilization of the bone components whatever their contour maybe and whatever final position they may occupy.

From the foregoing it will be seen that this invention is one welladapted toattain all of the ends and objectshereinbefore set forth,together with other advantages which areobvious-and which areinherent tothe invention.

It will be understood that certain features and subcombinations; are ofutility and may be employed without reference to other features andsubcombinations. This is contemplated by and is within the scope of theappended claims.

Inasmuch as various possible embodiments of the invention may be madewithout departing from the scope thereof, it is to be understood thatall matter herein set forth or shown in the accompanying drawings is tobe interpreted as illustrative and not in a limiting sense.

Having thus described my invention, I claim:

1. An osteotomy gauge for use with a femur having a cannulatedtransfixation nail extending axially of the femoral neck, comprising apin adapted to be advanced axially into the bore of said nail, anenlarged body carried by said pin and having normal to the pin a flatface adapted to engage the end of the nail and limit the advance of thepin into the nail, and an arm carried by said body and angularlyadjustable thereon relative to the plane of said face to lielongitudinally along the distal side of the femoral shaft when said pinis in said nail and said body is against the end of the nail.

2. An osteotomy gauge for use with a femur having a cannulated,transfixation nail extending axially of the femoral ncck, comprising apin adapted to be advanced axially into the bore of said nail, anenlarged body carried by said pin and having normal to the pin a fiatface adapted to engage the end of the nail and limit the advance of thepin into the nail, an arm carried by said body and angularly adjustablethereon relative to the plane of said face to lie longitudinally alongthe distal side of the femoral shaft when said pin is in said nail andsaid body is against the end of the nail, and means for locking said armimmovably to said body in adjusted position.

3. An osteotomy gauge for use with a femur having a cannulatedtransfixation nail extending axially of the femoral neck, comprising aslender pin of generally circular cross section adapted to be advancedaxially into the bore of said nail, an enlarged body carried by said pinand having normal to the pin a face adapted to engage the end of thenail and limit the advance of the pin into the nail, a rigid L-shapedmember having one leg mounted on said body, said one leg being angularlyadjustable relative to said face and at any angle being adjustable inthe direction of its own axis whereby the transverse leg of said membercan be positioned to lie longitudinally along the distal side of thefemoral shaft when said pin is in said nail and said body is against theend of the nail.

4. A gauge as in claim 3 wherein said legs of said L-shaped member areat right angles to one another.

5. An osteotomy gauge for use with a femur having a cannulatedtransfixation nail extending axially of the femoral neck, comprising aslender pin of generally circular cross section adapted to be advancedaxially into the bore of said nail, an enlarged body carried by said pinand having normal to the pin a face adapted to engage the end of thenail and limit the advance of the pin into the nail, a rigid L-shapedmember having one leg mounted on said body, said one leg being angularlyadjustable relative to said face and at any angle being adjustable inthe direction of its own axis whereby the transverse leg of said membercan be positioned to lie longitudinally along the distal side of thefemoral shaft when said pin is in said nail and said body is against theend of the nail, and means for locking said member immovably to saidbody in adjusted position.

6. An osteotomy gauge of the character described comprising a bodyhaving a fiat face, an arm pivoted to said body to swing about an axisparallel to said face, a pin carried by said body and projectingtherefrom normal to said face, said pin movable along said face towardand away from said axis thereby to adjust the spacing be tween said pinand said axis, and means for locking said pin in adjusted position.

7. An osteotomy gauge of the character described comprising a bodyhaving a flat face, an arm pivoted to said body to swing about an axisparallel to said face, means optionally operable to immobilize said armrelative to said body in any desired angular relationship, a pin carriedby said body and projecting therefrom normal to said face, said pinmovable along said face toward and away from said axis thereby to adjustthe spacing between said pin and said axis, and means for locking saidpin in adjusted position.

8. An osteotomy gauge of the character described comprising a bodyhaving a flat face, a rigid L-shaped member having one leg connected tosaid body for rotation and longitudinal movement relative to a fixedaxis parallel to said face, a pin carried by said body and projectingtherefrom normal to said face, said pin movable along said face towardand away from said axis thereby to adjust the spacing between said pinand said axis, and means for locking said pin in adjusted position.

9. An osteotomy gauge of the character described comprising a bodyhaving a flat face, a rigid L-shaped member having one leg connected tosaid body for rotation and longitudinal movement relative to a fixedaxis parallel to said face, means optionally operable when said memberis in any position to lock same against a change in its positionrelative to said body, a pin carried by said body and projectingtherefrom normal to said face, said pin movable along said face towardand away from said axis thereby to adjust the spacing between said pinand said axis, and means for locking said pin in adjusted position.

10. An osteotomy gauge of the character described comprising a bodyhaving a fiat face, a pivot pin carried by said body parallel to saidface, a rigid L-shaped member having an elongated hole in one legthereof to receive said pin whereby said leg is rotatable and axiallymovable about said pin, a second pin carried by said body and projectingtherefrom normal to said face, said pin movable along said face towardand away from said first pin thereby to adjust the spacing between saidpins, and means for locking said second pin in adjusted position.

11. An osteotomy gauge of the character described comprising a blockhaving a slot extending longitudinally inward from one end and dividingthe block into a pair of opposed legs, a pivot member bridging said slotand carried by said legs, a flat blade in said slot apertured to receivesaid pivot member whereby it is adapted to swing about said member,means including said pivot member for drawing said legs together toclamp said blade, an elongated pin disposed transverse to the length ofsaid slot and having a shank portion in said slot, said shank portion ofthe pin being shiftable in said slot toward and away from said pivotmember, and means optionally operable to secure said shank portion ofthe pin immovably to said block in any selected position along saidslot.

12. An osteotomy gauge of the character described comprising anelongated body having a fiat face, a pair of pivot pins carried by saidbody at the opposite ends thereof, each of said pins being parallel tosaid face, an arm pivotally mounted on one of said pins to swing in anare about said pin as a center, a rigid L-shaped member having in oneleg thereof an elongated aperture to receive the other pin whereby saidone leg is rotatable and axially movable on said other pin, said bodycarrying a third pin projecting therefrom normal to said face at aposition intermediate said first two pins, said third pin adjustablelongitudinally of said body to vary the spacing between same and therespective ends of said body, and means for securing said third pin tosaid body in any adjusted position.

13. An osteotomy gauge of the character described comprising a body, theopposite sides of which are flat parallel faces, an arm pivoted to saidbody to swing about an axis parallel to each of said faces, said bodyhaving a slot extending therethrough from one of said faces to theother, said slot being elongated in a direction normal 13 to said axis,a pin having a shank portion received in said slot, a pair of enlargedshoulder elements on said pin engaging opposite ones of said faces tomaintain the pin normal to said faces while allowing movement of saidshank longitudinally of the slot toward and away from said axis, one ofsaid shoulder elements being adjustable axially of the pin at will toclamp said body between the two elements and thereby restrain said pinagainst movement longitudinally of the slot.

14. An osteotomy gauge of the character described comprising a body, theopposite sides of which are flat parallel faces, a rigid L-shaped memberhaving one leg connected to said body for rotation and longitudinalmovement relative to a fixed axis parallel to each of said faces, saidbody containing a slot extending therethrough from one of said faces tothe other, said slot being elongated in a direction normal to said axis,an elongated pin having a shank portion received in said slot, a pair ofenlarged shoulder elements on said pin engaging opposite ones of saidfaces to maintain said pin normal thereto 20 while permitting it toslide longitudinally of the slot toward and away from said axis, one ofsaid shoulder elements being adjustable longitudinally of the pin atwill to clamp said body between the two shoulder elements and therebyrestrain the pin from movement in said slot.

References Cited in the file of this patent UNITED STATES PATENTS OTHERREFERENCES The Journal of Bone and Joint Surgery for April 1943, pp.319-339; The Journal of Bone and Joint Surgery for Oct. 1948, pp.1008-9. (Originals in the Scientific Library, copies in Div. 55.)

